*{
    margin: 0;
    padding: 0;
    list-style: none;
}
/* 导航栏 */
.nav{
    /* position: relative; */
    /* float: right; */
    height: 60px;
    width: 100%;
    margin: 0 auto;
    background: linear-gradient(45deg,rgb(74, 94, 110),rgb(93, 97, 105));
}
.page>img{
    margin: 0 40px;
    float: left;
    /* top: -10px; */
    width: 200px;
    height: 60px;
}
a{
    color:rgb(14, 16, 32);
    display: block;
    text-decoration: none;
}
.nav li{
    left: 50px;
    position: relative;
    width: 10%;
    height: 100%;
    line-height: 60px;
    letter-spacing: 2px;
    float: left;
    /* color: rgb(30, 36, 61); */
    margin: 0 auto;
    text-align: center;
    cursor: pointer;

}
.nav>li>a:hover{
    color: rgb(228, 243, 255);
    background-color: rgb(53, 70, 107);
}
.top>img{
    width: 100%;
}
/* out */
.out{
    position: relative;
    width: 100%;
    height: 850px;
    background: url("../images/back2.jpg") no-repeat;
    background-size: cover;
    filter: blur(4px);
}
/* middle */
.middle{
    position: absolute;
    width: 70%;
    top: 150px;
    left: 15%;
    height: 700px;
    background: url("../images/back3.png");
    background-size: 100% 100%;
    /* background-image: linear-gradient(to bottom, #3f4d65, #434f67, #485169, #4c546a, #50566c, #50566e, #4f5671, #4f5673, #495476, #43517a, #3c4f7d, #334d81); */
    opacity: 0.8;
}
.middle>p{
    color: rgb(234, 236, 241);
    font-size: 24px;
    line-height: 45px;
    text-align: center;
}
.middle>p>span{
    font-size: 35px;
    color: rgb(82, 128, 187);
}